Heart disease or cardiovascular diseases is the class of diseases that involve the heart or blood vessels (arteries and veins), which is the No. 1 cause of deaths in the United States. In most countries worldwide, the populations are facing high and increasing rates of cardiovascular diseases. Cancer (i.e., malignant neoplasm), as the No. 2 cause of deaths in the United States, is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). Cancer affects people at all ages with the risk for most types increasing with age. Cancer caused about 13% of all human deaths in 2007 (7.6 million). Most cancers are treated by surgery, radiation, chemotherapy, hormones, or immunotherapy. In the area of blood oxygenation, two main types of blood substitutes are in development, hemoglobin-based oxygen carriers (HBOCs) and perfluorocarbon emulsions (PFCs).
Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and a biological system's ability to readily detoxify the reactive intermediates or easily repair the resulting damage. Reactive oxygen species (ROS) are reactive molecules that contain the oxygen atom. They are very small molecules that include oxygen ions and peroxides and can be either inorganic or organic. They are highly reactive due to the presence of unpaired valence shell electrons. Reactive oxygen species can be beneficial, as they are used by the immune system as a way to attack and kill pathogens. Moreover, ROS form as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling. However, during times of environmental stress (e.g., UV or heat exposure) ROS levels can increase dramatically, which can result in significant damage to cell structures. This cumulates into the oxidative stress situation. ROS are also generated by exogenous sources such as ionizing radiation.
Reactive oxygen species are implicated in cellular activity to a variety of inflammatory responses including cardiovascular disease. They may also be involved in hearing impairment via cochlear damage induced by elevated sound levels, ototoxicity of drugs such as cisplatin, and in congenital deafness in both animals and humans. Redox signaling is also implicated in mediation of apoptosis or programmed cell death and ischaemic injury. Specific examples include stroke and heart attack. Generally, harmful effects of reactive oxygen species on the cell include DNA and RNA damage, oxidations of polydesaturated fatty acids in lipids (i.e., lipid peroxidation), oxidations of amino acids in proteins, and oxidative inactivation of specific enzymes by oxidation of co-factors.
All forms of life maintain a reducing environment within their cells. This reducing environment is preserved by enzymes that maintain the reduced state through a constant input of metabolic energy. Disturbances in this normal redox (reduction-oxidation reaction) state can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. In humans, oxidative stress is involved in many diseases, such as atherosclerosis, Parkinson's disease, heart failure, myocardial infarction, Alzheimer's disease, fragile X syndrome and chronic fatigue syndrome, but short-term oxidative stress may also be important in prevention of aging by induction of a process named mitohormesis. According to the Free-radical theory, oxidative damage initiated by reactive oxygen species is a major contributor to the functional decline that is characteristic of aging.
Treatment of various diseases (i.e., medical therapy) remains one of the most complex, intriguing, and challenging areas in industry, medicine, research, science, and technology. Therefore there is an ongoing need and interest to develop new methods and systems to improve disease treatment/management in various aspects.